The present invention relates to a personal identification system for comparing an article to which personal identification should be applied with a person using the article, for example for collating previously collected and preserved blood with the blood of a patient (donor) and confirming whether the stored blood is his own when the patient undergoes a surgical operation and uses the stored blood for transfusion.
The official gazette of Japanese Patent Laid-Open No. 343679/1994 (Japanese Patent Application No. 164047/1993) discloses a blood bag control method for performing self-blood transfusion. This system uses a card of a patient in which predetermined information such as the patient's code number, address, name, age, date of birth, body weight, type of blood, (ABO.Rh way), biochemical inspection items, presence or absence of infectious disease and type of them if any, and name of disease. Further the system uses a storage container for storing a blood bag which is provided with an electronic locking device. The electronic locking device is unlocked and a blood bag can be taken out from the storage container when the label of a card (e.g. clinical chart) of a patient is collated with the label of the storage container and coincides each other. Moreover, the above official gazette describes that the label attached to the taken-out blood bag is collated with the label of the patient's card to confirm them, the signature of the patient and the photograph of the patient's face are used, and a bar code is used for processing of the data of personal identification.
The above blood bag control system has the following problems:
1. In the case of collation according to the photograph of the patient's face, imperfect collation may occur due to change of the patient's face because of hospital treatment, change of the patient's face because of patient's anesthetic state, resemblance between strangers, or deterioration of the photograph due to a preservation temperature.
2. In the case of collation according to the signature of the patient, imperfect collation may occurred due to a physical condition of the patient, erroneous decision of the patient due to his anesthetic state, a case in which the patient cannot sign because of his invalid hand or finger, or presence of another patient with the same first and second names.
3. In the case of collation according to the control card of the patient, imperfect collation may occur due to a case in which the patient does not have his card when he undergoes a surgical operation or a case in which patient's cards are confused (though a method of embedding a non-contact information identification device using electromagnetic waves in the body of a patient is recently developed, there is a problem in view of morals).
Moreover, if the above items 1 and 3 are accidentally overlapped, patients are confused in the worst case and the blood of other person may be transfused under a state in which a patient cannot identify his own signature. It is the biggest problem of the above control system that a patient himself (individual) is not collated with an article to be identified (e.g. blood bag).
A bar code for processing the data for personal identification is widely used for supermarkets, retailers, OA, FA, medical treatment, libraries, and home delivery service, in which a numerical or alphabetical character is expressed in accordance with combination of widths of a white portion (space) and black portion (bar). However, the bar code has a low information density. Therefore, it is not realistic to bar-code personal identification data such as a fingerprint, palm shape, finger shape, or ear shape because it requires a large amount of data.